CVE-2024-39929

Exim through 4.97.1 misparses a multiline RFC 2231 header filename, and thus remote attackers can bypass a $mime_filename extension-blocking protection mechanism, and potentially deliver executable attachments to the mailboxes of end users.

CVSS v3.1 CNA

5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

EPSS

41.49% chance of exploitation in the next 30 days, 99th percentile

Published

2024-07-04

Updated

2025-03-18

Proof-of-concept exploits (2)

• michael-david-fry/CVE-2024-399294★ · 2024-08-01
• rxerium/CVE-2024-399293★ · 2025-10-14

Security advisories

• https://bugs.exim.org/show_bug.cgi?id=3099#c4
• https://git.exim.org/exim.git/commit/1b3209b0577a9327ebb076f3b32b8a159c253f7b
• https://git.exim.org/exim.git/commit/6ce5c70cff8989418e05d01fd2a57703007a6357
• Exim/exim/compare/exim-4.98-RC2...exim-4.98-RC3

References

• CVE Record
• NVD entry

Related

• CVE-2023-22622
• CVE-2025-24813
• CVE-2022-24086
• CVE-2022-41352
• CVE-2023-22515
• CVE-2023-40000